Project Summary ? Analytical Chemistry Core ? Core A The overall goal of the UC Davis CounterACT Center of Excellence is to identify and advance improved medical countermeasures for stopping seizures and preventing long-term consequences resulting from acute intoxication with chemical threat agents, specifically organophosphate cholinesterase inhibitors like diisopropylfluorophosphate (DFP), paraoxon and soman, or GABAA receptor blockers like tetramethylene- disulfotetramine (TETS) or picrotoxin. The Analytical Chemistry Core (Core A) is a central resource designed to provide state-of-the-art, comprehensive analytical support to Projects 1, 2, and 3, and the Probe and Pharmaceutical Optimization Core (Core B). Specifically, Core A will develop methods for the detection of target compounds and their metabolites by liquid chromatography?mass spectrometry (LC-MS) or gas chromatography?mass spectrometry (GC-MS), and provide quality control (QC) analysis of standard solutions prior to their use in projects. Core A will use these methods to perform mouse and rat ADME (absorption, distribution, metabolism, and excretion) studies for antiseizure drugs, anti-inflammatories and neuroprotectants to assist all Center projects in dose selection and time of administration post-exposure, and Core B in the optimization of novel therapeutic candidates. Core A will work with Project 2 and Project 3 to identify biomarkers of seizures and neuropathology to subsequently be used as a biochemical test of therapeutic efficacy. Metabolomics techniques, both targeted and global, will be employed. Targeted metabolomics will focus on oxylipins and neurosteroids, since expression of these signaling pathways are altered after a seizure, while global metabolomics will be employed as needed to identify broader biomarkers of seizure and therapy. Additionally, Core A will continue improving methods for TETS detection since the currently existing methods are too insensitive for pharmacokinetics (PK) analysis. During the first project period, Core A developed a rabbit polyclonal immunoassay for TETS, which will be optimized for high throughput laboratory use and for field detection. Core A has more recently initiated work to develop a nanobody- based assay. These small, heat stable reagents are inexpensive to produce and often provide valuable assays for the detection of small molecules in complex biological matrices. Immunoassays using both the polyclonal and the nanobody system will be optimized, and packaged in biosensor formats in a field deployable platform for on- site detection. When there is a clear need from the projects, immunoassays to other biomarkers of exposure and effect, including other neurotoxic chemicals, and their metabolites, will be created. Having a specialized core providing analytical support for all projects and cores improves efficiency and ensures consistency across all components of the CounterACT Center.